Electron beam tubes have been used in conventional systems for sterilizing fluids and other materials. For example, as described in U.S. Pat. No. 6,140,657, an electron beam tube can be used to create a plasma cloud used for sterilization. Electrons produced by a single cathode are emitted from a single, large window in the electron beam tube.
However, as taught by U.S. Pat. No. 6,140,657, there are numerous problems with this approach. The number of electrons emitted by conventional systems is low, and therefore, the overall energy of the electron beam is relatively low and unable to penetrate materials to any appreciable depth. Furthermore, conventional systems require placement of the object to be sterilized in a helium-filled and sealed chamber, thereby limiting the types of objects that can be being sterilized.